The present invention relates to ophthalmic solutions utilizing dodecyl-dimethyl-(2 phenoxyethyl)-ammonium bromide. The eye, and particularly the conjunctiva, offers an ideal environment for many types of organisms. Infections of the eye can be very serious. For example, Pseudomonas aeruginosa is a particularly dangerous and opportunistic organism, and has been known to cause infections which progress so rapidly that loss of the eye can occur in as short a period as twenty-four hours after onset. For this reason, it is important that solutions used in connection with the eye, such as preserved ophthalmic solutions and contact lens disinfecting solutions, be as effective antimicrobial agents as possible.
Presently, there is not a problem-free preservative available for ophthalmic use. Preservatives presently in use in ophthalmic solutions include benzalkonium chloride, chlorhexidine, Thimerosal and chlorobutanol. However, at the concentrations needed to be effective, these compounds have high ocular toxicity or sensitivity. For example, if used repeatedly in concentrations of 1:5,000 or stronger, benzalkonium chloride can denature the corneal protein causing irreversible damage. Other known preservatives, such as Onamer M and sorbic acid, are not very effective and therefore have short product shelf lives.
There exists, therefore, a need for improved ophthalmic solutions which are both effective as antimicrobial agents and which are also ocularly compatible.
There are several patents which disclose the use of quarternary ammonium compounds in contact lens solutions, including the following, but all of the disclosed compositions have certain disadvantages:
______________________________________ U.S. Pat. No. Inventor ______________________________________ 3,549,747 Krezanoski et al. 3,639,576 Kaspar et al. 4,013,576 Loshaek 4,029,817 Blanco et al. 4,039,662 Hecht et al. 4,361,548 Smith et al. ______________________________________
There also exists a need for improved ophthalmic solutions which have a longer shelf life.